1. Field of the Invention
The present invention relates to a data decoding system for a motion picture. More specifically, the invention relates to a motion picture decoding system in a multi-media data communication performing reproduction of motion picture utilizing MPEG (Motion) Picture Expert Group) data compressed into lesser amount of code than an original motion picture.
2. Description of the Related Art
An MPEG system which compresses a motion picture data requiring a large data amount, into lesser data amount by encoding, is a quite important technology in multi-media communication.
In a VOD (video on demand) system or so forth employing ATM (asynchronous transfer mode) communication, MPEG data is transmitted from a server (MPEG data transfer unit) to a CPU unit (multi-media communication terminal) utilizing communication protocol, such as TCP/IP (Transmission Control Protocol/Internet Protocol). The MPEG data to be transmitted is divided into groups of pictures (GOP). Inside of the GOP is further divided into a region called a header portion containing information other than video and audio data, such as time, ID number and so forth, and a region containing video and audio information. Therefore, reproduction of picture is performed by removing the header portion through process in the multi-media terminal for extracting only video and audio data and decoding the extracted video and audio data.
However, in the VOD system employing the ATM communication, while transmission of the MPEG data is performed with a communication protocol, such as TCP/IP, since CPU is used for transmission process, fluctuation of transmission speed can be caused depending upon process load on the multi-media terminal and/or server, such as application programs running thereon.
Namely, due to load of application, it is possible to cause delay in data transmission demand from the multi-media terminal or delay in data transmission timing from the server. Once such fluctuation of the transmission speed is caused, the reproduced picture on the multi-media communication terminal cannot be smooth, or delay in switching of the reproduction mode can be caused.